Hammer head with removable tip



Sept. 4, 1956 Filed Jan. 8, 1954 United rates Patent HAMMER HEAD WITH REMOVABLE TIP Frank Guida, Norwood, Mass.

Application January 8, 1954, Serial No. 403,009

2 Claims. (Cl. 145-36) This invention relates to hammer heads and more particularly to hammer heads having removable tips which can be replaced by tips of other materials or shapes. Machinists often have occasion to use hammers on subjects of different hardness. Hence it is frequently necessary or desirable to employ a hammer having a striking face of some preferred material such as copper, aluminum, synthetic resin or other material in place of the customary steel. It is an object of the present invention to provide a hammer head with a removable tip which can be secured in place or removed quickly and easily, which is securely held on the head when in place and which is secured by simple and economical means. A hammer head embodying the invention is hereinafter described in detail and is illustrated in the drawing, of which:

Figure 1 is a perspective view of a hammer having a head embodying the invention;

Figure 2 is a side elevation of the same, a portion being broken away to show in section on the line 22 of Figure 1;

Figure 3 is a plan view of a locking member;

Figure 4 is a section on the line 4-4 of Figure 7;

Figure 5 is a portion of Figure 2 without the removable tip;

Figure 6 is a section on the line 6-6 of Figure 5;

Figure 7 is an elevational view, partly broken away to show in section of a removable tip;

Figure 8 is a plan view of the tip shown in Figure 7; and

Figure 9 is a section similar to Figure 4 but with the tip in a different position.

The invention may be applied to the striking end or ends of any kind of hammer. In the example illustrated in the drawing a double ended hammer head 10 is shown with a removable tip 12 on a striking end. The body portion 14 has a short axial bore 16-of substantial diameter to receive a short stem 18 projecting axially from a tip 20. The stem 18 fits closely Within the bore 16 so that the shoulder 22 on the tip bears against the annular face 24 of the body 14 when the tip is in place. The stem 18 has a circumferential groove 26 the depth of which is equal to or slightly greater than the wire diameter of a stiff wire spring 30 which is shaped as indicated in Figure 3, an end of the wire being bent sharply inward as at 32 to enter a hole 34 extending inward from the bottom of the groove 26. A portion of the spring 30 adjacent to the end 32 and a portion 38 opposite the end 32 have the same center and radius of curvature as the groove 26 when the spring 30 is seated in the groove with the end 32 in the hole 34. The spring 30 has mutually opposed portions 40 and 42 which are arcuate but which normally bulge out from the groove 26 when the spring is mounted in the groove, as indicated in Figure 2. To receive the bulges 40 and 42 of the spring when the tip is applied to the body 14, the bore 16 is widened as at 44 for a portion of its depth, as indicated in Figures 5 and 6, these opposed widened areas being shaped to provide just enough clearance for the bulges 4i) and 42 and forming shallow longitudinal channels extending in just far enough to permit the shoulder 22 to seat on the face 24. In the wall of the bore 16 are two shallow arcuate opposed recesses 46, these recesses having an axial dimension equal to or slightly greater than the wire diameter of the spring 30. The recesses 46 are angularly spaced from the widened areas 44, as indicated in Figures 4, 6 and 9, and are at the inner end of the widened areas Where they form with the widened areas a set of four symmetrically arranged, radial recesses. When a tip 12 is applied to the body 14, the stem 18 is inserted into the bore 14, the bulges 40 and 42 of the spring 30 entering the widened area 44. The stem is moved in until the shoulder 22 engages the face 24, whereupon the spring 39 is opposite the recesses 46. The tip 12 is then turned 90 from the position shown in Figure 9 to that shown in Figure 4. Since the spring 38 is anchored to the stem 18 by the engagement of its inturned end 32 in the hole 34, the spring must turn with the tip 12. As the tip turns, the bulges 4i) and 42 are sprung inward as they engage and ride over the points 50 in the wall of the bore, then spring outward to enter the recesses 46, thus locking the tip 12 in place. To remove the tip, it is rotated a quarter turn from the position shown in Figure 4 to that shown in Figure 9, whereupon it can readily be withdrawn from the bore 16. Since considerable force, depending on the characteristics of the spring 30, is required to turn the tip 12, there is no danger of its working loose or coming off the head accidentally.

I claim:

1. A hammer head having a body portion and a removable tip secured thereto, said body portion having a short bore with shallow opposed longitudinal channels extending in from the outer end thereof and radial recesses spaced inward from the outer end thereof and angularly spaced from said channels, said head having a stem adapted to enter said bore, said stem having a circumferential groove and a spring member seated in said groove with portions bulging out of the groove to enter said channels and recesses, whereby rotative movement of said tip on said body portion locks said tip on said body portion and unlocks said tip for axial removal from said body portion.

2. A hammer head having a body portion and a removable tip secured thereto, said body portion having a short bore with shallow arcuate recesses in its wall, some of which recesses open in from the end of said body portion and some are undercut, said tip having a stem adapted to enter said bore, said stem having a circumferential groove, and a spring member mounted on said stem with portions thereof disposed in said groove and other portions bulging from said groove to engage alternatively in said open recesses or said undercut recesses according to the angular position of the tip relative to the body of the hammer whereby to lock or release said tip on said body.

References Cited in the file of this patent UNITED STATES PATENTS 334,283 Randall Jan. 12, 1886 337,474 Bartlett Mar. 9, 1886 1,862,352 Emrick June 7, 1932 2,537,244 Swett Ian. 9, 1951 2,540,937 Edens Feb. 6, 1951 

